a 0 exception is a null pointer exception. One of your pointers is uninitialized and empty.
This could be a matter of trying to access the child actors actor if it’s for instance still empty in c++ (just guessing atm)
It’s probably best to run your ide in debug mode and once the crash occurs check the callstack to see what last line of your code was executed before the fatal error.
If you are getting weird movement behavior then I would suggest checking if you are overriding any functions without calling the super version of the function (it invokes the parent’s function) it is usually called as the first thing in an override (though sometimes at a later stage in the function depending on circumstances)
Your ship may be having collision problems with the turret. If the ship is physics based it might get wonky. Try temporarily disabling collision on the turret actor to see if the ship stops misbehaving.
You may need to add the turrets to a custom collision channel so that they don’t interact with the parent ship.